In the known continuous furnaces of this kind, the conveyor belt forms in the muffle a plane support surface for the substrates. Because quality can be compromised during sintering due to the surface contact between the sintered layers and the conveyor belt, specially designed carrier devices are required for the substrates, which hold the substrates at the edges freely suspended above the conveyor belt. This permits this way making sintering without surface contact even for bottom-side layers. However, the disadvantages of these carrier devices are considerable, since the format can vary only within very narrow limits. The carriers are also partially exposed to heavy wear by high temperatures. The mass of the carrier can influence the sintering temperature profile or the temperature buildup time, and they cannot be operated with the usual automatic substrate loading systems.